2.1 The Messenger
A messenger is a man of highly noble and spiritual character chosen by Allah the Almighty to deliver to his people the commands of Allah revealed to him through an angel (Gabriel in most of the cases). Angels are creatures of Allah and they could be seen or heard with Allah's permission. Every messenger was sent to his own people except our beloved Prophet Muhammad (Peace be upon him) who was sent to the entire world and who is the last Prophet and Messenger of Allah to humankind.
Allah by His infinite wisdom choses to send human beings as His messengers to the people so that they could speak to people and counsel them. He wanted to send to the descendants of Adam one of them in order to guide them and call them to the Divine Path.